Furnace.



R. F. MCGOWAN.

FURNACE.

APPLICATION FILED JAN. 79. 1917.

Patented' foot. 23,1917.

nl @NN WMM/woo 9771, Q'

iinrrnn sfraans "raannfr ernten.

RICHARDE. ivrceowAN, or COLUMBUS, oHIo.

FURNAGE.

To all whom t may concern: Y

Be it known that I, RICHARD F. Mo- GowAN, a citizen of the United States, re siding at Columbus, in the county ofiFranklin and State of Ohio, have invented certain new and useful Improvements in Furnaces, of which the following isa specication.

This invention relates to furnaces particu larly adaptable for use in connection with power plants employing steam boilers. It is the object of this invention to provide a structure wherein smokeless combustion of the coal may be had. In accomplishing this, not only is the smoke nuisance eliminated, but also all of the heat units resulting from the combustion of the coal are utilized.

My invention, therefore, resides essentially in the provision of a unitary construction of furnace, wherein the refractory parts are heated to an incandescence more or less and these parts placed in the path of movement of the outgoing products of combustion so that the necessary heat is supplied to complete the combustion of all the coal. It is readily recognized that the volatile carbon products of coal may be expelled much more readily than the fixed carbon products and also that these volatile products are driven 0E very rapidly. If these are then brought into contact with highly heated surfaces, the likelihood of complete combustion is materially increased.

The preferred embodiment of my invention is shown in the accompanying sheet of drawings, in which similar characters of reference designate corresponding parts, and in which:

Figure 1 is a vertical longitudinal section showing my furnace applied to a return tubular type of boiler, as designated by line 1-1 of Fig. 2, and,

Fig. 2 is a transverse vertical sectionv taken on line 2-2 of Fig. 1.

In these drawings, the boiler is horizontally disposed and is designated by the reference numeral 1, heat being supplied to this boiler through the combustion of the fuel upon the grate bars 2. It will be noted that these grate bars occupy a small portion of the length of the boiler and are set in position to be on a slight incline. Located directly above these grate bars is an arch structure 3 preferably made of refractory material and consisting of a series of steps 4, 5, 6 and 7. Each of these steps gradually increases in thickness so that each Specification of Letters Patent.' Patented 0013.23', 19117. Application fue@ January ae, 19,17. serial No. 145,064. i Y

succeedingstep projects-to a level slightly beneath the next preceding. This acts somewhat `as abuffer for the outgoing products ofcombustion to slightly impede their progress without necessarilyv too greatly checking the draft. This actionheatsthe arch .to .a great extent and further, because of v.the stepped nature of this arch, a greater surface is exposed than if its under surface were smooth. To the rear of the grate and to the rear of the arch 3, there is located a second arch 8, which is also constructed of the same material of which the arch 3 is formed and this arch 8 also projects downwardly into the path of the outgoing products of combustion, therefore, slightlydeliecting their movement and also absorbing a portion of their heat. Located beneath andbetween these two arches is a bridge wall 9, whose lower portion is of the ordinary construction and is also made of refractory material. However, this bridge wall is capped by Va checker-work structure 10, which I have shown as being formed of a plurality of brick placed one upon another in such manner that. a plurality of openings is formed between them. In other` words, the bricks of each layer are slightly spacedfrom each other to'provide openings through which a portion of the outgoingY products of combustion may pass. This arrangement produces a very great area for absorbing the heat under certain conditions and for emitting this heat under other conditions such as when the volatile products are being rapidly liberated.

From the foregoing description, it will be apparent that after the two arch structures and the bridge wall cap are highly heated, the rapid liberation ofthe volatile carbons will be correspondingly heated in their outward passage and in this manner will effect their combustion to such extent as to prevent the escape of smoke. The heat used up to effect this combustion is then replaced to a much higher degree by the combustion of the products which come into contact with these refractory structures. It will, therefore,-be apparent that a very great heat radiating surface has been presented aside from the natural heat of the fuel bed and if the necessary quantity of air is then supplied, perfect combustion may be had. v

After passing the bridge wall 8, the prod- 110 ucts return vthrough the boiler tubes 11 and pass out to the stack 12 in the usual manner.

I/Vhat I claim, is:

l. In a furnace, a grate, a bridge Wall to the rear of said grate, an open 'checkerwork cap on said Wall made of refractory material and through the openings of which the products of combustion may pass, arefract'ory arch above said grate formed of a series of steps, each sl'ic'ceedng rearward .step pr jecting beneath the level of the preceding; and a secondi 'refractory'arch `located tothe rear of said bridge Wall.

2. In4 a furnace, a rearwardly and ldovvn- Wardly inclined grate, a bridge Wall immediately fo the rear of Said grate, Van open checkerwork cap on said Wall made of refractory materaland through the openings of Which the productsof combustion may "pass, a refractory arch above said grate formed of a series of steps, each succeeding rearward step projecting beneath the-level of the precedlng, and a second refractory larch -`located at'fche rear of said bridge Wall.

Gopes of this patentmy be obtained for five cents each; by addressing the "Commissioner of' Patents, Washington; 13.0. 

